"The singularity of Wittgenstein's Philosophical Investigations: Physiognomy of the Text" asks us what is the purpose of a physiognomy of a text. If someone raised that question, she would probably come to the conclusion that it had no purpose. Physiognomy is not one of the sciences. It is just a millenarian practice which happened to be considered, between the 18th and 19th centuries, as a sort of pseudoscience. Goethe, for instance, became interested for a while in that discipline as a form of constitution or presentation for a more serious project in the romantic science: the morphology. Viewing from this perspective, it may not be just a fortuitous coincidence that Wittgenstein, while drawing inspiration from Goethe's morphology, made a lot of considerations about physiognomy along almost all of his written production, from 1916 up to 1948. Such uses of "physiognomy" bring us in general to formulate questions that we normally would not do, and which could not also be answered, but which, on the other hand, reveal the kind of misunderstanding that led us to ask such questions. It is in that same sense that a physiognomy of the Philosophical Investigations reveals in the book a largely forgotten character of a philosophical text in the secondary literature.